The present invention relates to an automatic system for checking the integrity of pallets.
According to the UNI 5042:ISO 445, the term “pallet” denotes a horizontal platform characterised by a minimum height compatible with handling through transpallet carriages and/or fork lift trucks and other suitable handling equipment, used as support for collecting, storing, handling and transporting goods and loads; it can be constructed or provided with an upper structure.
FIG. 1 shows a traditional pallet checking system. It usually comprises an input transport device, indicated with reference numeral 11 in the figure, to which the pallet to be checked arrives in output from a de-palletising device, a stacker 12 and a de-stacker 13, arranged in series, which flicks through the stacks of new replenishing and/or feeding pallets for the palletising device.
Some types of pallets do not need being checked and are thus stacked by stacker 12, with the formed stack removed from the unit.
The system further comprises a pallet tilting device 14, at which the current direction of the tables of the upper surface of the pallet is determined with the aid of a photocell and thereby, if needed, the pallet is tilted by tilting device 14, so as to be properly orientated.
In series with tilting device 14 there is provided a device for checking the upper surface, indicated with reference numeral 15, which consists of a row of tracer rollers, which check the surface of the pallet with the tables parallel to the direction of advancement of the same pallet, whereas the 90° deviation block, indicated with reference numeral 16, changes the pallet advancement direction (from running front log side to running front short side); this operation is necessary for the type of pallet in which the direction of the tables of the lower pallet surface is orthogonal to that of the upper surface.
Moreover, in series with block 16 there is arranged a device for checking the lower surface, consisting of a series of tracer rollers, which check one of the surfaces of the pallet; in output from the system, broken pallets are deviated to a second stacker, indicated with reference numeral 18, which forms a stack of them, which is then removed by the system.
Finally, the output device, indicated with reference numeral 19, is used to transport non-faulty pallets to feed them to one or more palletising lines.
However, systems of this type are very complex and bulky and require production and operating costs that it would be desirable to reduce.